1. Field of the Invention This invention relates generally to a 6xc3x974 utility vehicle and more particularly to a 6xc3x974 utility vehicle having its mid-axle incorporate a suspension.
2. Description of the Prior Art
In prior art vehicles, a 6xc3x974 utility vehicle is a vehicle that has three axles. The front axle is used for steering and optionally has a suspension. The two rear axles are not suspended and are connected directly to the frame. Further, both of the rear axles typically are driven.
There is a very real perception by the purchasing public that a 6xc3x974 utility vehicle is very good. That is, the consumers think that the 6xc3x974 utility vehicle has better performance than a 4 wheel, 4 wheel drive vehicle. While it may be perceived as being better, there are serious problems with the 6xc3x974 that are not present with a regular 4-wheel utility vehicle. One of the problems is that the steering of a 6xc3x974 is quite poor. Once a payload is added to the vehicle, the rear four wheels all share pretty much equally the load. Since the four wheels are all bolted to the frame, steering is quite difficult as the payload increases. The rear wheels force the vehicle forward, even though the steering wheels are turned. Further, the ride predictability of a 6xc3x974 is difficult as there is constantly one of the four rear wheels that is off the ground when going through uneven terrain. This tends to throw the vehicle sideways and front to back. Further, the traction is not as good if the tires that are being driven are off the ground and steering is hindered when the front wheels are off of the ground. Another very important problem with a 6xc3x974 is that as one drives it up the hill and proceeds over the crest of the hill, the front wheels come off the ground until the vehicle hits the fulcrum point of the vehicle, then the vehicle teeters and falls forward onto the front wheels with the rear wheels coming off the ground.
The present invention addresses the problems associated with a 6xc3x974 utility vehicle and provides for a utility vehicle which has a suspended middle axle and a solid rear axle.
The invention is a utility vehicle having a frame and a front axle operatively connected to the frame. Two steerable wheels are operatively connected to the front axle. A rear axle is secured to the frame. The rear axle has operatively connected thereto two wheels. A middle axle is also operatively connected to the frame. The middle axle has first and second wheels operatively connected thereto. A suspension is provided for suspending the middle axle from the frame.
In a preferred embodiment, the middle axle suspension includes a torsional energy absorption member having an inner shaft member, an outer hollow member, and an elastomeric material operatively connecting the inner and outer members. A first trailing arm member has a first end operatively connected to the first wheel and a second end operatively connected to one of said members, the other of said members operatively connected to the frame. A second trailing arm member has a first end operatively connected to the second wheel and a second end operatively connected to one of said members, the other of said members operatively connected to the frame.